"Intego has discovered a new Trojan horse, OSX.Trojan.iServices.A, which is currently circulating in copies of Apple's iWork 09 found on BitTorrent trackers and other sites containing links to pirated software. The version of iWork 09, Apple's productivity suite, are complete and functional, but the installer contains an additional package called iWorkServices.pkg." Update: A new variant has been discovered in a pirated version of Adobe Photoshop CS4, alsoinformation about one target of a DDOS attack coming from the trojan.

Mac Applications are self contained bundles. All the libraries that they need are either statically linked or bundled together with the app. That's essentially what the .App bundles are. This is also why installing applications do not require root priviledges since they are not modifying any system directories.

This is very dangerous then. I have my Windows XP system configured in such a way that an executable can not both read and write from the same directories. In other words email me a virus and it won't execute. Viruses simply do not run under my username. NO exe can run under any directory that I can write to. When folks and PC bloggers figure out SRS policy you will realize how safe Windows XP has been since Service Pack 2.

When folks and PC bloggers figure out SRS policy you will realize how safe Windows XP has been since Service Pack 2.

That would certainly be nice, although I won't be holding my breath expecting it. Even as far back as Win2k, you could have reasonably-secure system just by running it with a normal user-level account - but from experience, even that is more hassle than most non-technical home users are willing to put up with.